Adolescents and young adults account for more new HIV infections than individuals in any other age group (CDC, 2008; UNICEF, UNAIDS, & WHO, 2002). High rates of risk-taking behavior among adolescents may be one explanation for the high incidence of HIV in this age group. In particular, unsafe sexual practices and substance use are two classes of behaviors in which adolescents frequently engage, and these behaviors place them at increased risk for HIV infection (CDC, 2010; Kotchick, Shaffer, Miller, & Forehand, 2001; Stein et al., 2000; Tapert, Aarons, Sedlar, & Brown, 2001; Temple & Leigh, 1992). Advancing understanding of the precursors and mechanisms related to adolescent engagement in these risky behaviors is crucial to reducing rates of infection among young people and, thus, has important public health implications. Converging evidence indicates that family variables and the manner in which individuals cope with distress and regulate emotions are important predictors of adolescent HIV risk behaviors (Brooks, Harris, Thrall, & Woods, 2002; Cooper, Russell, Skinner, Frone, & Mudar, 1992; DiClemente et al., 2001a, 2001b; Fromme & Rivet, 1994; Jaccard, Dittus, & Gordon, 1996; Perrino, Gonzlez-Soldevilla, Pantin, & Szapocznik, 2000). The goal of the proposed study is to further examine the link between parenting variables and adolescent HIV risk behaviors and to explore adolescents' strategies for coping with distress as a mechanism underlying this link. Specifically, the proposed study will examine the relations among parental responses to adolescents' negative emotions, adolescent suppression of distressing thoughts and emotions as a means of coping, and adolescent HIV risk behaviors-both concurrently and over time-using a multi-method study design that will include self-report, psychophysiological, and laboratory task data. [These data from adolescents (15-19 years old) and their parent(s) will be used to address three study aims: (1) To examine the concurrent link between parental responses to adolescents' negative emotions and adolescent HIV risk behaviors, and test whether adolescents' tendency to use suppression of distressing thoughts and emotions as a coping strategy mediates this link; (2) to examine the concurrent link between the suppression of distressing thoughts and emotions and adolescent HIV risk behavior, and test whether physiological arousal mediates this link; and (3) to examine the longitudinal link between parental responses to adolescents' negative emotions and adolescent HIV risk behaviors, and test whether adolescents' tendency to use suppression of distressing thoughts and emotions as a coping strategy mediates this link.] Results from the proposed study will be discussed in terms of their applicability to HIV prevention programs and their impact on public health.